Commit | Line | Data |
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8bc2021f EZ |
1 | /* BeginSourceFile tls.c |
2 | ||
3 | This file creates and deletes threads. It uses thread local storage | |
4 | variables too. */ | |
5 | ||
6 | #include <unistd.h> | |
7 | #include <stdlib.h> | |
8 | #include <stdio.h> | |
9 | #include <assert.h> | |
10 | #include <pthread.h> | |
11 | #include <semaphore.h> | |
12 | #include <errno.h> | |
13 | ||
14 | #define N_THREADS 3 | |
15 | ||
16 | /* Uncomment to turn on debugging output */ | |
17 | /*#define START_DEBUG*/ | |
18 | ||
19 | /* Thread-local storage. */ | |
20 | __thread int a_thread_local; | |
21 | __thread int another_thread_local; | |
22 | ||
23 | /* Global variable just for info addr in gdb. */ | |
24 | int a_global; | |
25 | ||
26 | /* Print the results of thread-local storage. */ | |
27 | int thread_local_val[ N_THREADS ]; | |
28 | int another_thread_local_val[ N_THREADS ]; | |
29 | ||
30 | /* Semaphores to make sure the threads are alive when we print the TLS | |
31 | variables from gdb. */ | |
32 | sem_t tell_main, tell_thread; | |
33 | ||
34 | ||
35 | void print_error () | |
36 | { | |
37 | switch (errno) | |
38 | { | |
39 | case EAGAIN: | |
40 | fprintf (stderr, "EAGAIN\n"); | |
41 | break; | |
42 | case EINTR: | |
43 | fprintf (stderr, "EINTR\n"); | |
44 | break; | |
45 | case EINVAL: | |
46 | fprintf (stderr, "EINVAL\n"); | |
47 | break; | |
48 | case ENOSYS: | |
49 | fprintf (stderr, "ENOSYS\n"); | |
50 | break; | |
51 | case ENOENT: | |
52 | fprintf (stderr, "ENOENT\n"); | |
53 | break; | |
54 | case EDEADLK: | |
55 | fprintf (stderr, "EDEADLK\n"); | |
56 | break; | |
57 | default: | |
58 | fprintf (stderr, "Unknown error\n"); | |
59 | break; | |
60 | } | |
61 | } | |
62 | ||
63 | /* Routine for each thread to run, does nothing. */ | |
64 | void *spin( vp ) | |
65 | void * vp; | |
66 | { | |
67 | int me = (long) vp; | |
68 | int i; | |
69 | ||
70 | /* Use a_global. */ | |
71 | a_global++; | |
72 | ||
73 | a_thread_local = 0; | |
74 | another_thread_local = me; | |
75 | for( i = 0; i <= me; i++ ) { | |
76 | a_thread_local += i; | |
77 | } | |
78 | ||
79 | another_thread_local_val[me] = another_thread_local; | |
80 | thread_local_val[ me ] = a_thread_local; /* here we know tls value */ | |
81 | ||
82 | if (sem_post (&tell_main) == -1) | |
83 | { | |
84 | fprintf (stderr, "th %d post on sem tell_main failed\n", me); | |
85 | print_error (); | |
86 | return; | |
87 | } | |
88 | #ifdef START_DEBUG | |
89 | fprintf (stderr, "th %d post on tell main\n", me); | |
90 | #endif | |
91 | ||
92 | do | |
93 | { | |
94 | errno = 0; | |
95 | #ifdef START_DEBUG | |
96 | fprintf (stderr, "th %d start wait on tell_thread\n", me); | |
97 | #endif | |
98 | if (sem_wait (&tell_thread) == -1) | |
99 | { | |
100 | if (errno != EINTR) | |
101 | { | |
102 | fprintf (stderr, "th %d wait on sem tell_thread failed\n", me); | |
103 | print_error (); | |
104 | return; | |
105 | } | |
106 | #ifdef START_DEBUG | |
107 | fprintf (stderr, "th %d wait tell_thread got EINTR, rewaiting\n", me); | |
108 | #endif | |
109 | } | |
110 | } | |
111 | while (errno == EINTR); | |
112 | ||
113 | #ifdef START_DEBUG | |
114 | fprintf (stderr, "th %d Wait on tell_thread\n", me); | |
115 | #endif | |
116 | ||
117 | } | |
118 | ||
119 | void | |
120 | do_pass() | |
121 | { | |
122 | int i; | |
123 | pthread_t t[ N_THREADS ]; | |
124 | int err; | |
125 | ||
126 | for( i = 0; i < N_THREADS; i++) | |
127 | { | |
128 | thread_local_val[i] = 0; | |
129 | another_thread_local_val[i] = 0; | |
130 | } | |
131 | ||
132 | if (sem_init (&tell_main, 0, 0) == -1) | |
133 | { | |
134 | fprintf (stderr, "tell_main semaphore init failed\n"); | |
135 | return; | |
136 | } | |
137 | ||
138 | if (sem_init (&tell_thread, 0, 0) == -1) | |
139 | { | |
140 | fprintf (stderr, "tell_thread semaphore init failed\n"); | |
141 | return; | |
142 | } | |
143 | ||
144 | /* Start N_THREADS threads, then join them so that they are terminated. */ | |
145 | for( i = 0; i < N_THREADS; i++ ) | |
146 | { | |
147 | err = pthread_create( &t[i], NULL, spin, (void *) (long) i ); | |
148 | if( err != 0 ) { | |
149 | fprintf(stderr, "Error in thread %d create\n", i ); | |
150 | } | |
151 | } | |
152 | ||
153 | for( i = 0; i < N_THREADS; i++ ) | |
154 | { | |
155 | do | |
156 | { | |
157 | errno = 0; | |
158 | ||
159 | #ifdef START_DEBUG | |
160 | fprintf (stderr, "main %d start wait on tell_main\n", i); | |
161 | #endif | |
162 | if (sem_wait (&tell_main) == -1) | |
163 | { | |
164 | if (errno != EINTR) | |
165 | { | |
166 | fprintf (stderr, "main %d wait on sem tell_main failed\n", i); | |
167 | print_error (); | |
168 | return; | |
169 | } | |
170 | #ifdef START_DEBUG | |
171 | fprintf (stderr, "main %d wait tell_main got EINTR, rewaiting\n", i); | |
172 | #endif | |
173 | } | |
174 | } | |
175 | while (errno == EINTR); | |
176 | ||
177 | #ifdef START_DEBUG | |
178 | fprintf (stderr, "main %d wait on tell_main\n",i); | |
179 | #endif | |
180 | } | |
181 | ||
182 | #ifdef START_DEBUG | |
183 | fprintf (stderr, "main done waiting on tell_main\n"); | |
184 | #endif | |
185 | ||
186 | i = 10; /* Here all threads should be still alive. */ | |
187 | ||
188 | for( i = 0; i < N_THREADS; i++ ) | |
189 | { | |
190 | if (sem_post (&tell_thread) == -1) | |
191 | { | |
192 | fprintf (stderr, "main %d post on sem tell_thread failed\n", i); | |
193 | print_error (); | |
194 | return; | |
195 | } | |
196 | #ifdef START_DEBUG | |
197 | fprintf (stderr, "main %d post on tell_thread\n", i); | |
198 | #endif | |
199 | } | |
200 | ||
201 | for( i = 0; i < N_THREADS; i++ ) | |
202 | { | |
203 | err = pthread_join(t[i], NULL ); | |
204 | if( err != 0 ) | |
205 | { | |
206 | fprintf (stderr, "error in thread %d join\n", i ); | |
207 | } | |
208 | } | |
209 | ||
210 | i = 10; /* Null line for setting bpts on. */ | |
211 | ||
212 | } | |
213 | ||
214 | int | |
215 | main() | |
216 | { | |
217 | do_pass (); | |
218 | ||
219 | return 0; /* Set breakpoint here before exit. */ | |
220 | } | |
221 | ||
222 | /* EndSourceFile */ |